54 UNIVERSALITY OF DEGENERATIVE EVOLUTION 



was attained by the predominance of the fourth toe, 

 accompanied by the almost total extinction of the 

 other toes. The persistence of the fourth toe 



FIG. 25. Righf fore-paw 

 of Kangaroo. 



c, calcaneum; a, astraga- 

 lus ; cb, cuboid ; n, os 

 centrale; cn.third cunei- 

 form. II, III, IV, V, 

 second, third, fourth 

 and fifth digits, the 

 second and third being 

 degenerate. (After 

 Flower's Introduction 

 to the Osteology of the 

 Mammalia.) 



FIG. 26. Chceropus. 



Right fore-paw, 

 c, calcaneum ; a, astragu- 

 lus ; n, os centrale ; c6, 

 cuboid; <, 3e, third 

 cuneiform; II, III. IV, 

 V, second, third, 

 fourth and fifth digits, 

 of which the second, 

 third and fifth are de- 

 generating. (After 

 Flower's Introduction 

 to the Osteology of the 

 Mammalia.') 



FIG. 27. -Right hind-paw 

 of Tarsius Spectrum. 



c, calcaneum ; a, astragu- 

 lus; r, navicular; c 1 , c 2 , 

 <#, first, second, and 

 third cuneiforms ; c6, 

 cuboid ; I, II, III, IV, 

 V, first, second, third 

 and fourth digits. (After 

 Flower's Introduction 

 to the Osteology of the 

 Mammalia.) 



instead of the third is accounted for . by the 

 previous arboreal existence of marsupials before 

 they became adapted to leaping. 



(c) The Tarsius (Tarsius spectrum). The tarsius, 

 which is a small lemur, is to be found in Celebes. 



